1. Field
The disclosed embodiments relate to a propulsive assembly for aircraft comprising a jet engine and a heat exchanger. More specifically, the disclosed embodiments deal with the routing of the cooling air and of the hot air to the heat exchanger in which said flows are intended to circulate. The disclosed embodiments also relate to a position of the heat exchanger relative to the jet engine.
2. Brief Description of Related Developments
It is known that, to feed the air conditioning circuit of the pressurized cabin containing the crew and the passengers of an aircraft, compressed air must be taken from the compressors of the jet engines of said aircraft. This compressed air is routed by ducts from the jet engines to the air conditioning circuit of the pressurized cabin. However, in as much as the temperature of the air taken from the compressors of the jet engine is very high, normally greater than 400° C., it is vitally important to first cool this compressed air.
For this, it is known that a heat exchanger can be used to at least partially cool the compressed air taken from a compressor of the jet engine before injecting it into the air conditioning circuit. The heat exchanger comprises a housing in which a flow of hot air, originating from the compressor of the jet engine, crosses a flow of cooling air, taken from the fan case ducting of the jet engine. The cold air taken from the fan case ducting of the jet engine has a temperature in the region of 70° C. to 100° C. When the flows cross, there is a heat exchange making it possible, on leaving the housing of the heat exchanger, to obtain a sufficiently cooled compressed air, that is having a temperature of approximately 200° C. The flow of cooled hot air is then directed to the air conditioning circuit, whereas the flow of cooling air is discharged from the jet engine through openings provided in the cowl of the engine strut, or strut for fixing the jet engine to the wings of the aircraft.
One of the drawbacks of the heat exchanger is its bulk. In practice, the heat exchanger is more often than not positioned at the strut used to link the jet engine to a wing of the aircraft. Generally, the heat exchanger is joined to a top face of the strut. More specifically, the heat exchanger is fitted above the front part of the box forming the rigid structure of the strut, and inside the fairing covering said box. It is therefore necessary to lead the flow of hot air, that has to be cooled, and the flow of cooling air, that is to be used to cool the flow of hot air, from the jet engine situated under the strut, to the heat exchanger situated above the strut.
Currently, because of the position of the heat exchanger on the strut and the fact that the cold air and the hot air are taken from the jet engine, the hot air and cooling air intake ducts both pass through the strut box. The strut box is a working structure of the strut, which is weakened where the ducts pass through its structure. Moreover, the bulk of the ducts in the internal volume of the box is large, forcing said ducts to cross inside the box. Such crossings can make it difficult to fit cooling air and hot air intake ducts on the jet engine and the heat exchanger.
Moreover, the cold air is currently taken laterally on the jet engine, at the fan case ducting, so that the cooling air intake duct, used to bring the flow of cooling air from the jet engine to the heat exchanger, must pass through the cowl of a thrust reverser of the jet engine. Now, the cowl of the thrust reverser has a kinematic whereby it can have a closed position and an open position. Thus, when the cowl of the thrust reverser is open, the link between the cooling air intake duct and the cowl of the reverser cannot be made. It is therefore necessary to provide a link system with a seal to enable a leak-free coupling between the cooling air intake duct and the cowl of the reverser to be made.